Affinity is a 2008 UK film adaptation of Sarah Waters' 1999 novel of the same name; directed by Tim Fywell and written by Andrew Davies. It stars Zoë Tapper, Anna Madeley, Domini Blythe, Amanda Plummer, and Mary Jo Randle. The film was nominated for the GLAAD Media Award for Outstanding TV Movie or Limited Series.
Affinity is set in Victorian England; the story of an upper-class young woman, Margaret (Anna Madeley), she was suffering from depression after the death of her father and the rejection of her best friend. A mysterious girl named Selina soon catches her eye. After an initial curiosity and attraction, their relationship builds slowly. She becomes obsessed with her mysterious friend, and the pair begins to bristle under the watchful eyes of the prison guards, particularly the head matron, who suspects that the two women are "sweet on" each other. As the story progresses through Selina's shady background, and Margaret's dislike of her home life; a plot to break out of the prison develops. But just what the plan is, and who calls the shots is yet to be discovered.